Order: Ampicillin (Principen) 150 mg PO every 6 hours
Available: Ampicillin (Principen) 125mg per 5 ml
How many mL of ampicillin are needed for one dose?
( Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero. TYPE THE ANSWER ONLY, no label )
The Correct Answer and Explanation is:
Answer: 6.0
To calculate how many milliliters (mL) of ampicillin are needed for one dose, follow these steps:
- Identify the prescribed dose: The order is for 150 mg of Ampicillin.
- Identify the concentration of the available solution: The available concentration is 125 mg per 5 mL. This means that 5 mL of the solution contains 125 mg of Ampicillin.
- Calculate the amount of solution required to obtain 150 mg of Ampicillin:
- First, determine the concentration in mg/mL. You have 125 mg in 5 mL, so the concentration is calculated as follows:Concentration (mg/mL)=125 mg5 mL=25 mg/mL\text{Concentration (mg/mL)} = \frac{125 \text{ mg}}{5 \text{ mL}} = 25 \text{ mg/mL}Concentration (mg/mL)=5 mL125 mg=25 mg/mL
- Now, use this concentration to find out how many mL are needed to get 150 mg of Ampicillin. Set up a proportion where xxx is the volume in mL:Concentration=150 mgx mL\text{Concentration} = \frac{150 \text{ mg}}{x \text{ mL}}Concentration=x mL150 mg Since Concentration=25 mg/mL, we have:\text{Since } \text{Concentration} = 25 \text{ mg/mL}, \text{ we have:}Since Concentration=25 mg/mL, we have: 25 mg/mL=150 mgx mL25 \text{ mg/mL} = \frac{150 \text{ mg}}{x \text{ mL}}25 mg/mL=x mL150 mg
- Solve for xxx by rearranging the formula:x=150 mg25 mg/mL=6 mLx = \frac{150 \text{ mg}}{25 \text{ mg/mL}} = 6 \text{ mL}x=25 mg/mL150 mg=6 mL
- Round the answer to the nearest tenth: In this case, the calculation results in exactly 6.0 mL.
- Verify the dose: Double-check that the concentration and volume calculations are consistent with the prescribed dose.
By following these calculations, you ensure that you administer the correct volume of medication based on the concentration of the solution provided.